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World J Gastroenterol. Mar 14, 2014; 20(10): 2470-2481
Published online Mar 14, 2014. doi: 10.3748/wjg.v20.i10.2470
Unraveling the ties between irritable bowel syndrome and intestinal microbiota
Sung Noh Hong, Poong-Lyul Rhee
Sung Noh Hong, Poong-Lyul Rhee, Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea
Author contributions: Hong SN and Rhee PL participated in conception and design of the paper, and analysis of the literature data; Hong SN provided the first draft of the manuscript; Rhee PL was involved in critical discussion and revision of the manuscript for the intellectual content.
Correspondence to: Poong-Lyul Rhee, MD, PhD, Professor, Chairman, Division of Gastroenterology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50 Irwon-dong, Gangnam-gu, Seoul 135-710, South Korea. plrhee@skku.edu
Telephone: +82-2-34103409 Fax: +82-2-34106983
Received: October 2, 2013
Revised: November 26, 2013
Accepted: January 3, 2014
Published online: March 14, 2014
Processing time: 161 Days and 2 Hours
Abstract

Irritable bowel syndrome (IBS) is the most prevalent functional gastrointestinal disorder. It is a multifactorial disorder. Intestinal microbiota may cause the pathogenesis of IBS by contributing to abnormal gastrointestinal motility, low-grade inflammation, visceral hypersensitivity, communication in the gut-brain axis, and so on. Previous attempts to identify the intestinal microbiota composition in IBS patients have yielded inconsistent and occasionally contradictory results. This inconsistency may be due to the differences in the molecular techniques employed, the sample collection and handling methods, use of single samples that are not linked to fluctuating symptoms, or other factors such as patients’ diets and phenotypic characterizations. Despite these difficulties, previous studies found that the intestinal microbiota in some IBS patients was completely different from that in healthy controls, and there does appear to be a consistent theme of Firmicutes enrichment and reduced abundance of Bacteroides. Based on the differences in intestinal microbiota composition, many studies have addressed the roles of microbiota-targeted treatments, such as antibiotics and probiotics, in alleviating certain symptoms of IBS. This review summarizes the current knowledge of the associations between intestinal microbiota and IBS as well as the possible modes of action of intestinal microbiota in the pathogenesis of IBS. Improving the current level of understanding of host-microbiota interactions in IBS is important not only for determining the role of intestinal microbiota in IBS pathogenesis but also for therapeutic modulation of the microbiota.

Keywords: Irritable bowel syndrome; Intestinal microbiota; Dysbiosis; Antibiotics; Probiotics

Core tip: The intestinal microbiota is altered in some Irritable bowel syndrome (IBS) patients, and the symptoms of IBS can be alleviated by treatments that target the microbiota. Over the past several years, many studies have attempted to identify the intestinal microbiota composition in IBS patients and intestinal dysbiosis in IBS is characterized by Firmicutes enrichment and reduced abundance of Bacteroides. Based on the differences in intestinal microbiota composition, the roles of microbiota-targeted treatments, such as antibiotics and probiotics, were investigated in alleviating certain symptoms of IBS.